<p>Given an integer array nums, return all the triplets <code>[nums[i], nums[j], nums[k]]</code> such that <code>i != j</code>, <code>i != k</code>, and <code>j != k</code>, and <code>nums[i] + nums[j] + nums[k] == 0</code>.</p> <p>Notice that the solution set must not contain duplicate triplets.</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> nums = [-1,0,1,2,-1,-4] <strong>Output:</strong> [[-1,-1,2],[-1,0,1]] <strong>Explanation:</strong> nums[0] + nums[1] + nums[2] = (-1) + 0 + 1 = 0. nums[1] + nums[2] + nums[4] = 0 + 1 + (-1) = 0. nums[0] + nums[3] + nums[4] = (-1) + 2 + (-1) = 0. The distinct triplets are [-1,0,1] and [-1,-1,2]. Notice that the order of the output and the order of the triplets does not matter. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> nums = [0,1,1] <strong>Output:</strong> [] <strong>Explanation:</strong> The only possible triplet does not sum up to 0. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> nums = [0,0,0] <strong>Output:</strong> [[0,0,0]] <strong>Explanation:</strong> The only possible triplet sums up to 0. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 <= nums.length <= 3000</code></li> <li><code>-10<sup>5</sup> <= nums[i] <= 10<sup>5</sup></code></li> </ul>